The use of blow-molding as a method for manufacturing various sorts of articles is generally well known. Typically, this process involves the use of a mold consisting of two separate halves or portions having cavities of particularly desired shapes and sizes. Usually, one extrudes a large-diameter, sealed tube of molten material (commonly referred to as a “parison”), places the tube between the mold halves, and closes the mold around the tube. Fluid pressure is then introduced into the tube, forcing the molten tube against the walls of the cavities, conforming the tube to the shape thereof. The pressure is maintained until the molten material cools and solidifies. The pressure is then released, the mold halves are pulled apart, and the hardened article is ejected therefrom.
Before the blow molded part is removed from the mold, it is typically separated from excess parison material called flash. This step can be completed in-mold or can involve secondary operations. Typically, once the parison is extruded between the mold halves, it is pinched off at the top and/or bottom and then blown into a part that takes the shape of the mold cavity. The pinch-off generates excess plastic material in the form of top and/or bottom flash.
Flash generation imposes limits on blow molding efficiency. In some cases, Flash removal is done with an in mold blade as shown and described in U.S. Pat. Pub. No. 20130175739, the content of which is incorporated by reference herein.
Although the above referenced publication discusses various parts, systems, methods and/or features that can be used to the task of flash removal in mold, in cases where the part is joined to another part, an improved seal is desired and therefore such improved parts, machinery and methods of manufacture are desired.